The invention relates to electric fabric articles for heating/warming.
Techniques known for augmenting heating/warming capabilities of clothing fabric include adding electric wires to the fabric, typically by incorporating the wires directly into the fabric or by attaching the wires to the ,fabric, e.g., by sewing. It is also known, e.g., from Gross et al. U.S. Pat. No. 4,021,640, to print an electrical circuit with a resistance heating element on a sheet of plastic, such as MYLAR(copyright), and to incorporate strips of the plastic sheet into a fabric article, such as a glove.
According to one aspect of the invention, an electric heating/warming composite fabric article comprises a fabric layer having an inner surface and an outer surface, a barrier layer disposed at the inner surface of the fabric layer, the barrier layer having an inner surface and an outer surface, and an electric heating/warming element in the form of a flexible, electricity-conducting film disposed upon the inner surface of the barrier layer and adapted to generate heating/warming when connected to a power source. Preferably, the outer layer of the barrier layer is secured at least adjacent, and, more preferably, secured, to the inner surface of the fabric layer.
According to another aspect of the invention, an electric heating/warming composite fabric article comprises at least a fabric layer having an inner surface and an outer surface, and an electric heating/warming element in the form of a flexible, electricity-conducting film disposed upon the inner surface of the fabric layer and adapted to generate heating/warming when connected to a power source. Preferably, the composite fabric article further comprises a barrier layer positioned at least adjacent to the inner surface of the fabric layer.
Preferred embodiments of one or both aspects of the invention may include one or more of the following additional features. The film forming the electric heating/warming element is also stretchable. The fabric layer may be hydrophobic or hydrophilic. The barrier may be micro-porous hydrophobic, e.g. poly tetrafluoroethylene (PTFE), and/or nonporous hydrophilic, e.g. poly urethane, or a combination of both. The barrier layer is resistant to passage of air and water droplets, and permeable to water vapor. The electric heating/warming element is washable, non-swelling and hydrophobic. The electric heating/warming element is resistant to stiffening and cold crack. The electric heating/warming element has resistivity in the range of about 100 (1xc3x97102) ohm-cm to 0.000001 (1xc3x9710xe2x88x926) ohm-cm. The electricity-conducting film comprises synthetic resin, preferably containing conductive particles, e.g., comprising at least one of silver and graphite.
According to another aspect of the invention, a method of forming an electric heating/warming composite fabric article comprises providing a fabric layer having an inner surface and an outer surface and a barrier layer having an inner surface and an outer surface, joining the inner surface of the fabric layer to the outer surface of the barrier layer, applying an electricity-conducting paste upon the inner surface of the barrier layer in a predetermined pattern of an electric circuit, and curing the electricity-conducting paste to form an electric heating/warming element in the form of a flexible, electricity-conducting film defining an electric circuit upon the inner surface of the barrier layer, the electric heating/warming element being adapted for connection to a power source, thereby to generate heating/warming.
According to another aspect of the invention, a method of forming an electric heating/warming composite fabric article comprises providing a barrier layer having an inner surface and an outer surface, applying an electricity-conducting paste upon the inner surface of the barrier layer in a predetermined pattern of an electric circuit, curing the electricity-conducting paste to form an electric heating/warming element in the form of a flexible, electricity-conducting film defining an electric circuit upon the inner surface of the barrier layer, providing a fabric layer having an inner surface and an outer surface, and joining the inner surface of the fabric layer to the outer surface of the barrier layer, the electric heating/warming element being adapted for connection to a power source, thereby to generate heating/warming.
According to yet another aspect of the invention, a method of forming an electric heating/warming composite fabric article comprises providing a fabric layer having an inner surface and an outer surface, applying an electricity-conducting paste upon the inner surface of the fabric layer in a predetermined pattern of an electric circuit, and curing the electricity-conducting paste to form an electric heating/warming element in the form of a flexible, electricity-conducting film defining an electric circuit upon the inner surface of the fabric layer, the electric heating/warming element being adapted for connection to a power source, thereby to generate heating/warming. Preferably, the method further comprises the steps of: providing a barrier layer having an inner surface and an outer surface, and positioning the outer surface of the barrier layer at least adjacent to the inner surface of the fabric layer, to overlay at least a portion of the electric heating/warming element.
Preferred embodiments of one or more of these various aspects of the invention may include one or more of the following additional features. During the curing step. the electricity conducting paste is cured to form a stretchable film defining the electric circuit. The method comprises the further step of incorporating the electric heating/warming composite fabric article into articles of apparel, e.g. jackets, hats, gloves, shirts, pants, socks, boots, and/or shoes, and/or into home furnishings textile articles, e.g. blankets, warmers and/or seat pads. The method comprises the further step of connecting the electric heating/warming element to a power source, thereby to generate heating/warming.
It is an objective of this invention to provide an electric heating/warming composite fabric article which is windproof, water-resistant and water vapor permeable, and, in selected applications, stretchable.
It is a further objective of this invention to provide an electric heating/warming element formed of a material which is flexible, washable, non-swelling and hydrophobic, and, preferably, stretchable, that may be deposited on the surface of a fabric layer, or on the surface of a barrier layer that is, or may after be, adhered to a fabric layer.
Other objectives of the invention include to provide a heating/warming composite fabric article which is stretchable, making it comfortable to wear; to provide a heating/warming composite fabric article which is waterproof, but also vapor permeable, e.g., making it particularly suitable for use in winter garments; and to provide a heating/warming composite fabric article in which the heating/warming elements are resistant to stiffening and cracking at low temperatures.
Other features and advantages of the invention will be apparent from the following description of a presently preferred embodiment, and from the claims.